Feat: add auto connection for pw ports

Dockerfile

@@ -25,11 +25,13 @@ RUN apt update --allow-releaseinfo-change && \
 ENV TZ=Europe/Vienna
 RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
 RUN mkdir -p /srv/src /srv/tests /srv/config srv/logs srv/socket /var/audio
+RUN mkdir -p /etc/wireplumber/scripts
 COPY src /srv/src
 COPY tests /srv/tests
 COPY config/sample.engine-core.docker.ini /srv/config/engine-core.ini
 COPY Makefile /srv/Makefile
 COPY VERSION /srv/VERSION
+COPY scripts/wireplumber /etc/wireplumber
 COPY scripts/entrypoint.sh /srv/entrypoint.sh
 
 RUN groupadd --gid ${AURA_GID} aura && \

scripts/wireplumber/auto-connect-ports.lua

+-- As explained on: https://bennett.dev/auto-link-pipewire-ports-wireplumber/
+--
+-- This script automatically connects the audio device specified to liquidsoap.
+-- Thanks to Bennett Hardwick <me@bennetthardwick.com> 
+
+-- Link two ports together
+function link_port(output_port, input_port)
+  if not input_port or not output_port then
+    return false
+  end
+
+  local link_args = {
+    ["link.input.node"] = input_port.properties["node.id"],
+    ["link.input.port"] = input_port.properties["object.id"],
+
+    ["link.output.node"] = output_port.properties["node.id"],
+    ["link.output.port"] = output_port.properties["object.id"],
+    
+    -- The node never got created if it didn't have this field set to something
+    ["object.id"] = nil,
+
+    -- I was running into issues when I didn't have this set
+    ["object.linger"] = true,
+
+    ["node.description"] = "AURA Link created by auto_connect_ports"
+  }
+
+  local link = Link("link-factory", link_args)
+  link:activate(1)
+
+  return true
+end
+
+function delete_link(link_om, output_port, input_port)
+  print("Trying to delete")
+
+  if not input_port or not output_port then
+    print("No ports")
+    return false
+  end
+
+  local link = link_om:lookup {
+    Constraint {
+      "link.input.node", "equals", input_port.properties["node.id"]
+    },
+    Constraint {
+      "link.input.port", "equals", input_port.properties["object.id"],
+    },
+    Constraint {
+      "link.output.node", "equals", output_port.properties["node.id"],
+    },
+    Constraint {
+      "link.output.port", "equals", output_port.properties["object.id"],
+    }
+  }
+
+  if not link then
+
+    print("No link!")
+
+    return
+  end
+
+  print("Deleting link!")
+
+  link:request_destroy()
+end
+
+-- Automatically link ports together by their specific audio channels.
+--
+-- ┌──────────────────┐         ┌───────────────────┐
+-- │                  │         │                   │
+-- │               FL ├────────►│ AUX0              │
+-- │      OUTPUT      │         │                   │
+-- │               FR ├────────►│ AUX1  INPUT       │
+-- │                  │         │                   │
+-- └──────────────────┘         │ AUX2              │
+--                              │                   │
+--                              └───────────────────┘
+-- 
+-- -- Call this method inside a script in global scope
+--
+-- auto_connect_ports {
+--
+--   -- A constraint for all the required ports of the output device 
+--   output = Constraint { "node.name"}
+--
+--   -- A constraint for all the required ports of the input device 
+--   input = Constraint { .. }
+--
+--   -- A mapping of output audio channels to input audio channels
+--
+--   connections = {
+--     ["FL"] = "AUX0"
+--     ["FR"] = "AUX1"
+--   }
+--
+-- }
+--
+function auto_connect_ports(args)
+  local output_om = ObjectManager {
+    Interest {
+      type = "port",
+      args["output"],
+      Constraint { "port.direction", "equals", "out" }
+    }
+  }
+
+  local input_om = ObjectManager {
+    Interest {
+      type = "port",
+      args["input"],
+      Constraint { "port.direction", "equals", "in" }
+    }
+  }
+
+  local all_links = ObjectManager {
+    Interest {
+      type = "link",
+    }
+  }
+
+  local unless = nil
+
+  if args["unless"] then
+    unless = ObjectManager {
+      Interest {
+        type = "port",
+        args["unless"],
+        Constraint { "port.direction", "equals", "in" }
+      }
+    }
+
+  end
+
+  -- handle the connect argument
+  function _connect()
+    local delete_links = unless and unless:get_n_objects() > 0
+
+    for output_name, input_name in pairs(args.connect) do
+      local output = output_om:lookup { Constraint { "port.name", "matches", string.format("*%s", output_name) }}
+      local input =  input_om:lookup { Constraint { "port.name", "matches", string.format("*%s", input_name) }}
+
+      if delete_links then
+        delete_link(all_links, output, input)
+      else
+        link_port(output, input)
+      end
+    end
+  end
+
+  output_om:connect("object-added", _connect)
+  input_om:connect("object-added", _connect)
+  all_links:connect("object-added", _connect)
+
+  output_om:activate()
+  input_om:activate()
+  all_links:activate()
+
+  if unless then
+    unless:connect("object-added", _connect)
+    unless:connect("object-removed", _connect)
+    unless:activate()
+  end
+end
+
+-- 
+-- Fill in your port.alias and port.name
+--
+
+-- Auto connect Yamaha sink to the first two channels of the Yamaha
+local audio_source_input = os.getenv("AUDIO_SOURCE_INPUT")
+local audio_source_output = os.getenv("AUDIO_SOURCE_OUTPUT")
+local audio_channel_left = os.getenv("AUDIO_CHANNEL_LEFT")
+local audio_channel_right = os.getenv("AUDIO_CHANNEL_RIGHT")
+
+print(string.format("%s_*", audio_source_input))
+auto_connect_ports {
+  output = Constraint { "port.alias", "matches", audio_source_output .. "_*" },
+  input = Constraint { "port.alias", "matches", "lq_in:*" },
+  connect = {
+    [audio_channel_left] = "in_0",
+    [audio_channel_right] = "in_1"
+  }
+}
+auto_connect_ports {
+  output = Constraint { "port.alias", "matches", "lq_out:*" },
+  input = Constraint { "port.alias", "matches", audio_source_input .. "_*" },
+  connect = {
+    ["out_0"] = audio_channel_left,
+    ["out_1"] = audio_channel_right
+  }
+}
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